Fast Walking Speed Research Articles

ASSOCIATIONS BETWEEN WALKING SPEED AND GUT MICROBIOME DIVERSITY IN OLDER MEN FROM THE MROS STUDY

Abstract While gut dysbiosis has been linked to frailty in aging, its association with early mobility impairments is unclear. Here, our primary goal was to determine the cross-sectional associations between walking speed and gut microbiome in 740 older men (84±4y) from MrOS with available stool samples and 400m walking speed measured in 2014–16. We also analyzed the retrospective longitudinal associations between changes in 6-meter walking speed (from 2005-06 to 2014-16) and gut microbiome composition among participants with available data (702/740). The gut microbiome composition was determined by 16S sequencing (DADA2 and SILVA). We examined diversity, taxa abundance (by ANCOM-BC), and performed network analysis (by NetCoMi) to uncover microbial communities interactions by walking speed levels. Higher walking speed (m/s) was associated with greater microbiome Shannon α-diversity (R=0.11; P=0.004). Decline in walking speed was associated with lower Shannon α-diversity (R=0.07; P=0.054). Faster walking speed and less decline in walking speed were associated with higher abundance of genus-level bacteria that produce short-chain fatty acids, and possess anti-inflammatory properties, including Paraprevotella, Fusicatenibacter, and Alistipes, adjusting for age, race, site, education, health, marital status, weight, height, physical activity, batch, medications, energy, and fiber intake (P< 0.05). The gut microbiome networks of participants in the first vs. last quartile of walking speed (≤0.9 vs. ≥1.2 m/s) exhibited distinct characteristics, including different cluster numbers, hubs, and centrality measures (P< 0.05). Faster walking speed and its less decline were associated with higher gut microbiome diversity, suggesting potential role of microbiome in preserving mobility in aging.

Lateral flexion of a compliant spine improves motor performance in a bioinspired mouse robot.

A flexible spine is critical to the motion capability of most animals and plays a pivotal role in their agility. Although state-of-the-art legged robots have already achieved very dynamic and agile movement solely relying on their legs, they still exhibit the type of stiff movement that compromises movement efficiency. The integration of a flexible spine thus appears to be a promising approach to improve their agility, especially for small and underactuated quadruped robots that are underpowered because of size limitations. Here, we show that the lateral flexion of a compliant spine can promote both walking speed and maneuver agility for a neurorobotic mouse (NeRmo). We present NeRmo as a biomimetic robotic mouse that mimics the morphology of biological mice and their muscle-tendon actuation system. First, by leveraging the lateral flexion of the compliant spine, NeRmo can greatly increase its static stability in an initially unstable configuration by adjusting its posture. Second, the lateral flexion of the spine can also effectively extend the stride length of a gait and therefore improve the walking speeds of NeRmo. Finally, NeRmo shows agile maneuvers that require both a small turning radius and fast walking speed with the help of the spine. These results advance our understanding of spine-based quadruped locomotion skills and highlight promising design concepts to develop more agile legged robots.

The relationship between depressive symptoms and physical performance in postmenopausal women: a cross-sectional investigation.

The relationship between depressive symptoms and declining physical performance in postmenopausal women has been extensively examined. However, various confounding factors can influence this association. This study aimed to investigate the link between depressive symptoms and physical performance in postmenopausal women while considering potential interfering factors. In this cross-sectional study, 137 postmenopausal women were categorized into two groups based on the presence of depressive symptoms (n = 58; mean ± SD age, 60.12 ± 8.45 y) and absence of depressive symptoms (n = 79; mean ± SD age, 60.72 ± 7.45) using the Geriatric Depression Scale (short version) (GDS-15). Thoracic kyphosis angle was measured using the flexicurve method. Physical performance was assessed through various tests, including Timed Up and Go, Five Times Stand and Sit Test, 6-minute Walking Speed, 10-meter Usual Walking Speed, 10-meter Fast Walking Speed, and dynamometry. The study compared variables between the two groups and used linear regression models adjusted for dynamometry, kyphosis angle, age, antidepressant usage, sitting time, and fall history to evaluate the relationship between GDS-15 scores and physical performance. Significant differences were observed in physical performance, body mass index, kyphosis angle, antidepressant usage, sitting time, and fall history between women with and without depressive symptoms. The GDS-15 showed a negative association with all walking speed tests (10-meter Usual Walking Speed, m/s; P < 0.001; B = -0.01; 10-meter Fast Walking Speed, m/s; P < 0.001; B = -0.02; 6-minute Walking Speed, m/s; P < 0.004; B = -0.01) and a positive association with the Five Times Stand and Sit Test ( P < 0.002; B = 0.21) and Timed Up and Go ( P < 0.001; B = 0.13) tests, regardless of grip strength, kyphosis angle, age, antidepressant use, sitting time, or fall history in postmenopausal women. This study underscores the independent and substantial impact of depressive symptoms on the physical performance of postmenopausal women. These findings emphasize the importance of addressing both mental health and physical well-being when providing care and support for this demographic.

Determinants of successful cognitive aging over 15 years: a population‐based study

AbstractBackgroundAlthough aging is related to loss in cognitive function, some individuals maintain high levels of cognitive performance also in late life. However, studies mapping longitudinal cognitive trajectories are scarce and little is known about the factors that may promote successful cognitive aging (SCA). We sought to identify predictors of SCA, based on latent profiles derived from interindividual differences in rate of change across several cognitive domains.MethodWe followed 1,966 individuals from the Swedish National Study on Aging and Care in Kungsholmen (SNAC‐K) over 15 years (mean baseline age = 71.6 years; 62.9% female). Participants were free from dementia at baseline and had undergone at least two cognitive assessments during follow‐up. Cognition was assessed with a comprehensive battery, including tests of semantic memory, episodic recall and recognition, letter and verbal fluency, and executive function. We estimated level and change within each of the cognitive domains with linear mixed effect models, based on which we classified participants into successful, normal, or decline groups. These groups were used to derive profiles of overall cognitive change trajectories, through latent class analysis. We then investigated demographic, health, lifestyle, and genetic predictors of profile membership.ResultWe obtained three latent cognitive profiles. 31.6% of the sample was classified as successful, 50.6% as normal, and 17.8% as decliner. In multi‐adjusted multinomial logistic regression analysis, membership in the successful profile was predicted by female sex, higher education, and a faster walking speed (ps &lt; 0.003). Current smoking, feelings of loneliness, and carrying the Apolipoprotein ԑ4‐allele were associated with a lower likelihood of being classified as successful (ps &lt; 0.037). Higher age, diagnosis of diabetes or depression, and being an ԑ4‐carrier increased the likelihood of being classified into the decline profile (ps &lt; 0.026).ConclusionWe identified several demographic, lifestyle, health, and genetic factors of SCA. Of note, these factors were different from those that predicted accelerated cognitive decline. Although some cognitive loss may be an inevitable part of aging, our results suggest certain modifiable factors (i.e. smoking and quality of social interactions) to be related to maintained cognitive function in older age.

The role of ankle and knee muscle characteristics in spatiotemporal gait parameters at different walking speeds: A cross-sectional study

BackgroundUnderstanding the intricate interplay between ankle and knee muscle characteristics and their impact on gait parameters is crucial for enhancing our comprehension of human locomotion, particularly in the context of varying walking speeds among healthy young adults. Research question: The study aimed to identify the relative importance of ankle and knee flexor and extensor muscle characteristics (e.g., strength estimated by peak torque [PT] and rate of torque development [RTD]) in the spatiotemporal gait parameters and variability in self-selected (SSWS) and fast walking speeds (FWS) in healthy young adults. MethodsOne hundred and thirty-nine adults (75 men – 54% and 64 women – 46%; 29.04 ± 9.55 years) were assessed about their muscle characteristics (PT and RTD by an isokinetic dynamometer) and spatiotemporal gait parameters at different walking speeds (SSWS and FWS by an instrumented walkway). ResultsData analysis indicated a weak relationship between the PT and RTD of the ankle and knee and spatiotemporal gait parameters and variability in both walking conditions (SSWS: R2 0.14–0.05; FWS: R2 0.40–0.05). The strength of the knee muscles was more relevant when walking at a self-selected speed, while the strength of the ankle muscles played a more prominent role when walking at a fast pace. SignificanceThe findings underscore the critical role of ankle muscles (plantar and dorsiflexors) at fast walking speeds. Therefore, targeted interventions for strength and optimization of these muscles are paramount.

Relationship between quadriceps muscle computed tomography measurement and motor function, muscle mass, and sarcopenia diagnosis.

The quadriceps muscle is one of the human body's largest and most clinically important muscles and is evaluated using mid-thigh computed tomography (CT); however, its relationship with motor function and sarcopenia remains unclear. Herein, we investigated the relationship between the cross-sectional area (CSA) of the quadriceps muscle, CT attenuation value (CTV), dual-energy X-ray absorptiometry muscle mass measurements, and muscle strength and motor function to evaluate the relationship between muscle mass loss and motor function decline, determine the diagnostic ability for sarcopenia, and confirm the usefulness of quadriceps muscle CT evaluation. A total of 472 middle-aged and older community dwellers (254 men and 218 women) aged ≥40 years (mean age: 62.3 years) were included in this study. The quantity and quality of the quadriceps muscle were assessed using CSA and CTV (CSA×CTV) as a composite index multiplied by quality and quantity. Age-adjusted partial correlations by sex with eight motor functions (knee extension muscle strength, power, normal walking speed, fast walking speed, grip strength, sit-up ability, balance ability, and reaction time) were evaluated, including correction methods for height, weight, and body mass index (BMI). Further, the accuracy of sarcopenia diagnosis was evaluated using appendicular muscle mass with dual-energy X-ray absorptiometry measurements, grip strength, and walking speed as the gold standard, and receiver operating characteristic curves were plotted to evaluate diagnostic performance. In men, CSA and CSA×CTV were significantly associated with seven of the eight motor functions (p<0.05), excluding only balance ability. BMI-corrected CSA was significantly correlated with all eight motor functions in men and women (p<0.05). In the diagnosis of sarcopenia based on skeletal muscle index, CSA (area under the curve (AUC) 0.935) and CSA×CTV (AUC 0.936) and their correction by height (CSA/height (AUC 0.917) and CSA×CTV/height (AUC 0.920)) were highly accurate and useful for diagnosis in men but moderately accurate in women (CSA (AUC 0.809), CSA×CTV (AUC 0.824), CSA/height (AUC 0.799), CSA×CTV/height (AUC 0.814)). The present results showed that a single CT image of the quadriceps muscle at the mid-thigh is useful for diagnosing sarcopenic changes, such as loss of muscle mass, muscle weakness, and muscle function.

Fast walking reduces the risk of breast cancer: evidence from a Mendelian randomisation study

ABSTRACT Breast cancer is a prevalent malignancy that poses a serious threat to women’s health. Lifestyle modifications can alter the risk of breast cancer. Walking is a common lifestyle behaviour, but its impact on breast cancer remains unclear. We conducted a Mendelian randomisation (MR) study to explore this issue. Independent genetic variants closely associated with usual walking speed were selected as instrumental variables from publicly available genome-wide association studies (GWAS) databases. Genetic data on the estrogen receptor (ER) status of breast cancer and breast cancer were obtained from a large-scale GWAS meta-analysis. Inverse variance-weighted regression analysis revealed that brisk walking speed was associated with a lower risk of breast cancer [OR = 0.69; 95%CI = (0.54, 0.88); P = 0.006] and lower risk of ER− breast cancer [OR = 0.60; 95%CI = (0.38, 0.91); P = 0.018]. However, walking speed was not associated with the risk of ER + breast cancer [OR = 0.92; 95%CI = (0.70, 1.25); P = 0.641]. MR-Egger intercept and MR-PRESSO tests did not reveal significant levels of pleiotropy or heterogeneity, respectively. Sensitivity analyses also confirmed the robustness of the results. Our study provides strong evidence that faster walking speeds may reduce the risk of breast cancer and that a more widespread adoption of moderate or high-intensity exercise may be effective in reducing women’s health risks.

Norms for Usual and Fast Walking Speed in Adults 45-69 Years Old From the French General Population: Constances Study

ObjectivesWalking speed (WS) represents an objective measure of motor function and health. We aimed to develop usual (UWS) and fast WS (FWS) norms for the general population using a regression-based approach, while considering age, sex, height, and education. DesignCross-sectional analysis of a population-based study. Setting and ParticipantsFrench Constances study (45-69 years). MethodsUWS/FWS were measured over 3 m (dynamic start) using photoelectric cells. We addressed selection effects (related to survey sampling and nonresponse) and missing data using a combination of inverse probability weighting (IPW) and multiple imputation (MI). Norms by sex, age, height, and education (<tertiary/≥tertiary) were estimated using a 3-level linear mixed effects model (random effects on center and year) allowing for nonlinear relations that were adjusted for age, sex, height, education, and significant 2-way interactions. ResultsAnalyses are based on 44,772 participants (51.2% women) with a mean age of 56.8 years (SE = 0.2) for women and 57.3 years (SE = 0.2) for men, and a mean height of 161.4 cm (SE = 0.1) for women and 174.2 cm (SE = 0.1) for men after IPW/MI. WS estimates decreased after IPW/MI. The mean UWS was 116.9 cm/s (SE = 0.8) in women and 120.7 cm/s (SE = 0.8) in men, and the mean FWS was 168.7 cm/s (SE = 1.0) in women and 182.8 cm/s (SE = 1.2) in men. In the multiadjusted model, UWS/FWS decreased with age and increased with height and education. Men had faster FWS than women; they had slightly slower UWS than women in the low-education group, but there were no sex differences in the high-education group. Conclusions and ImplicationsWe developed UWS/FWS norms by age, sex, height, and education for the French general population (45-69 years) that are available through a web app (https://cesp-proxy2.vjf.inserm.fr/NORMES-VM-EN/). These norms can be used to identify in midlife persons with lower motor performances than the general population, given their age, sex, height, and education, who are at higher risk of adverse outcomes.

Using SUpported Motivational InTerviewing (SUMIT) to increase physical activity for people with knee osteoarthritis: a pilot, feasibility randomised controlled trial

ObjectiveThe objective of this study was to determine the feasibility and effectiveness of using SUpported Motivational InTerviewing (SUMIT) to increase physical activity in people with knee osteoarthritis (KOA).DesignRandomised controlled trial.SettingWe...

Spatiotemporal Gait Parameters and Gait Asymmetry in Patients With Lumbar Disc Herniation, Treated With Microdiscectomy: A Prospective, Observational Study.

The aim of this study was to emphasize on the interaction of spatial and temporal gait parameters and analyse the gait asymmetry in the patients with lumbar disc herniation (LDH) before and after microdiscectomy. This was a prospective, observational study conducted on 59 cases of LDH planned for lumbar microdiscectomy, and healthy control group with 54 participants for analysis was performed prior to surgery and 15 days after surgery. The spatiotemporal gait parameters were measured using a "Win-Track" gait analysis platform system. All the participants walked barefoot for 10 times with their normal walking speed in the same day. The 3 flawless walking data were recorded and the arithmetic means were computed. The gait symmetry index was used to calculate the walking asymmetry. The pain intensity of the patients was recorded shortly before performing the analysis by a visual analogue scale. In the postoperative assessment LDH patients had significantly shorter temporal parameters, longer spatial parameters, faster walking speed, and more cadence than the preoperative assessment (p < 0.05). There were improvements in the asymmetry values of the postoperative gait parameters compared to the preoperative values, but these differences were not significant (p > 0.05). In addition, there was a significant difference in all parameters in terms of gait asymmetry between the postoperative assessment and the healthy controls (p < 0.05). These results can guide the patient-specific evaluating and implementation of gait rehabilitation programs, and design protocols before or after surgery in the LDH patients.

The Impact of Neurorehabilitation on the Motor Function and Independence Patients with Post-Stroke Hemiplegia

Objective: To explore the effect of neurorehabilitation on the motor function and independence of patients with post-stroke hemiplegia. Methods: 62 stroke patients from August 2020 to August 2022 with hemiplegia were selected for this study. The patients were randomly divided into a study group (neurorehabilitation) and a control group (conventional rehabilitation). Gait changes, National Institutes of Health Stroke Scale (NIHSS), activities of daily living (BI index), motor function (Fugl-Meyer), quality of life (SF-36) and treatment satisfaction of both groups were compared. Results: The stride length (SL) and the fastest walking speed within 10 m (10 mMWS) of the research group were better than those of the control group (P &lt; 0.05). The NIHSS, Barthel Index, Fugl-Meyer, SF-36, and other scores of the research group were better than those of the control group (P &lt; 0.05). The treatment satisfaction of the study group was higher than that of the control group, P &lt; 0.05. Conclusion: Neurorehabilitation is highly effective and feasible in improving walking speed, increasing stride length, and reducing nerve function damage in stroke patients with hemiplegia.

A pelvis-oriented margin of stability is robust against deviations in walking direction

The Margin of Stability (MOS) is often assessed relative to the intended, linear path of walking progression. When an unanticipated or irregular change in direction occurs, such as during a sudden turn or during activities of daily living, distinguishing the lateral from anteroposterior MOS can be challenging. The purpose of this study was to assess an anatomically orientated method of calculating the MOS using the pelvic orientation to define lateral and anteroposterior directions. We hypothesized that when straight walking was disrupted with a curved path, the pelvis-oriented MOS measure would be less variable compared to the global-oriented MOS measure. We recruited 16 unimpaired participants to walk at preferred and fast walking speeds along a straight walking path, as well as a path with an exaggerated, curvilinear deviation. We determined the within-subject mean and standard deviation of the anterior MOS at mid-swing and the posterior and lateral MOS at ipsilateral foot strike. For straight walking and curved walking separately, repeated measures factorial ANOVAs assessed the effects of model (global or pelvis-oriented), limb (left or right), and speed (preferred or fast) on these MOS values. Based on reduced variability during curved walking, the pelvis-oriented MOS was more robust to walking deviations than the globally defined MOS. In straight walking, the pelvis-oriented MOS was characterized by less lateral and more anterior stability with differences exacerbated by faster walking. These results suggest a pelvis-oriented MOS has utility when the path of progression is unknown or unclear.

Concurrent validity of walking speed measured by a wearable sensor and a stopwatch during the 10-meter walk test in individuals with stroke

BackgroundWalking speed is often measured with a stopwatch throughout stroke recovery. Wearable sensors also have been used recently to measure walking speed and provide information about spatiotemporal characteristics of walking.Research Question:Do walking speeds measured with stopwatch and APDM wearable sensors have concurrent validity? MethodsIndividuals with chronic stroke (n = 62) performed the 10-meter walk test at comfortable and maximal speeds. Walking speeds were measured with a stopwatch and APDM Opal wireless wearable sensors (3-unit). Tests of concurrent validity between stopwatch and APDM (Bland-Altman plots, systematic and proportional bias, and intraclass correlations) and test-retest reliability between trials (intraclass correlations, standard error of measurement, and minimal detectable change) were performed. ResultsWalking speeds measured with APDM were ∼0.07 m/s slower than those measured with stopwatch (systematic bias; t ≥ 13.1, p < 0.001). Intraclass correlations ranged from poor to excellent. There were greater differences in walking speeds between APDM and stopwatch for individuals with faster walking speeds (proportional bias). Test-retest reliability was excellent for both APDM and stopwatch (intraclass correlation≥0.94). Standard error of measurement ranged from 0.04 to 0.07 m/s and minimal detectable change ranged from 0.10 to 0.19 m/s.Significance:It may be inappropriate to use walking speed measurements from APDM sensors and stopwatch interchangeably in individuals with chronic stroke. Differences in walking speeds may reflect stopwatch error or the derivation of walking speed from wearable sensors. Test-retest reliability was excellent for both stopwatch and APDM, but minimal detectable change values were large. Large changes in walking speed may be required to be confident that the change is a true and clinically meaningful change and not measurement error. The validity and reliability of measuring walking speed with wearable sensors in individuals with chronic stroke has important implications for determining community ambulation, assessing improvements after rehabilitation, and developing exercise prescriptions.

Autonomic nervous system and postural control regulation during orthostatic test as putative markers of physical resilience among community-dwelling older adults

IntroductionWe examined whether autonomic nervous system (ANS) and postural control regulation during orthostatic test reflect physical resilience by studying their associations with maximal walking speed and mortality. MethodsThe participants were community-dwelling Finnish men (n = 303) and women (n = 386) aged 75, 80, and 85 years at baseline. Systolic and diastolic blood pressure (BP), heart rate, heart rate variability (HRV), respiratory rate, and postural sway were obtained using a digital sphygmomanometer, a single-channel ECG, and thigh- and chest-worn accelerometers. Linear and Cox regression models were used to estimate the associations of the physiological indices with maximal 10-m walking speed and 5-year mortality separately for sexes. ResultsBetter maintenance of BP under orthostatic stress was associated with faster walking speed in women and lower mortality hazard in men. Greater HRV in terms of low frequency power and lower respiration rate in supine position and smaller orthostatic changes in these were associated with faster walking speed especially in women. Less postural sway after standing up was associated with faster walking speed in women (−0.057, SE 0.022, p = 0.011) and more postural sway with increased mortality hazard in men (HR 1.71, 95 % CI 1.20–2.43) even after controlling for BP responses. ConclusionsIn addition to ANS regulation at rest and under stress, adaptation of postural control system to orthostasis may be used in quantifying older adults' physical resilience. Wearable sensors capturing stimulus-response patterns and natural fluctuations of body functions may provide opportunities to monitor and incorporate different subsystems' resilience also in free-living conditions.

Which trunk muscle parameter is the best predictor for physical function in older adults?

BackgroundDespite preliminary evidence demonstrating the relevance of trunk muscle strength for physical function in older adults, it is not clear which muscle-related trunk parameter is the best predictor for physical functions. Therefore, this study aimed to compare trunk muscle morphology or strength parameters regarding their predictive ability for physical functions. MethodsSeventy-four older adults (38 men, 36 women, mean age 76.85 years) were tested for maximum absolute and relative isokinetic trunk flexion and extension strength, trunk lean mass, and trunk muscle quality. Functional assessment included normal and fast walking speed, repeated sit-to-stand transfer, timed up and go, and postural sway during a closed-feet and a semi-tandem stance adjusted for body height. Pearson's correlations were used to compare relationship between trunk strength adjusted and unadjusted for body weight to physical functions. Linear regression analysis including sex and age as co-variables was performed between trunk muscle and functional test parameters. ResultsRelative back extension strength was the most consistent significant predictor for all physical function tests (p = 0.004–0.04) except for postural sway. Relative trunk flexion strength was related to normal walking speed (p = 0.024). Trunk lean mass was related to timed up and go performance (p = 0.024). ConclusionRelative back extension strength is associated with better performance in nearly all standard tests for physical function in older adults, while trunk flexion strength and lean mass seem to play a minor role. Our findings emphasize the importance of trunk muscle strength, especially the back extensor muscles, for physical function in older adults.

Association between walking speed early after admission and all-cause death and/or re-admission in patients with acute decompensated heart failure.

Patients with heart failure (HF) frequently experience decreased physical function, including walking speed. Slower walking speed is associated with poorer prognosis. However, most of these reports focused on patients with stable HF, and the relationship between walking speed in acute phase and clinical outcomes is unclear. Therefore, we aimed to investigate the associations between walking speed early after admission and clinical events in patients with acute decompensated HF (ADHF). We reviewed consecutive 1391 patients admitted due to ADHF. We measured walking speed the first time to walk on the ward more than 10 m after admission, and the speed within 4 days after admission was included in this study. The primary outcome was combined events (all-cause death and/or re-admission due to HF). The follow-up period was up to 1 year from the discharge. The study population had a median age of 74 years [interquartile range (IQR): 65-80 years], and 35.9% of patients were females. The median walking speed was 0.70 m/s (IQR: 0.54-0.88 m/s). Combined events occurred in 429 (30.8%) patients. Faster walking speed was independently associated with lower rate of combined events (adjusted hazard ratio per 0.1 m/s increasing: 0.951, 95% confidence interval: 0.912-0.992). Faster walking speed within 4 days after admission was associated with favourable clinical outcomes in patients with ADHF. The results suggest that measuring walking speed in acute phase is useful for earlier risk stratification.

Consistency of muscle activation signatures across different walking speeds

BackgroundUsing a machine learning algorithm, individuals can be accurately identified from their muscle activation patterns during gait, leading to the concept of individual muscle activation signatures. Research questionAre muscle activation signatures robust across different walking speeds? MethodsWe used an open dataset containing electromyographic (EMG) signals from 8 lower limb muscles in 50 asymptomatic adults walking at 5 speeds (extremely slow, very slow, slow, spontaneous, and fast). A machine learning approach classified the EMG profiles based on similar (intra-speed classification) or different (inter-speed classification) walking speeds as training and testing conditions. ResultsIntra-speed median classification rates of muscle activation profiles increased with walking speed, from 92 % for extremely slow, to 100 % for self-selected fast walking conditions. Inter-speed median classification rates increased when the speed of the training condition was closer to that of the testing condition. Higher median classification rates were found across slow, spontaneous, and fast walking speed conditions, from 56 % to 96 %, compared with classification rates involving extremely and very slow walking speed conditions, from 6 % to 62 %. SignificanceOur findings reveal that i) muscle activation signatures are detectable for a large range of walking speeds, even those involving different gait strategies (intra-speed median classification rates from 92 % to 100 %), and ii) muscle activation signatures observed during very low walking speeds are not consistent with those observed at higher speeds, suggesting a difference in motor control strategy. Caution should therefore be exercised when assessing gait deviations of a slow walking patient against a normative database obtained at higher speed. Identifying the robustness of individual muscle activation signatures across different movements could help in detecting changes in motor control, otherwise difficult to detect on classical time-varying EMG patterns.

No Difference Between One-shot Co-injection of Corticosteroids and Hyaluronic Acid in a Three-injection Regimen for Knee Osteoarthritis: A Randomized, Double-blind Trial [RETRACTED

Although many guidelines now recommend against hyaluronic acid (HA) injections alone for the nonoperative management of knee osteoarthritis (OA), prior studies have disagreed about whether adding an intra-articular corticosteroid to HA results in sufficient benefit to justify the potential dose-dependent and time-dependent chondrotoxicity of corticosteroids. (1) Do patients with knee OA treated with low-dose intra-articular corticosteroids and HA administered under ultrasound guidance have more favorable patient-reported knee OA-related outcomes from 1 to 26 weeks after treatment than those treated with ultrasound-guided HA injections alone? (2) Do patients treated with a corticosteroid co-injection exhibit more favorable physical functional performance than those treated with injections of HA alone? We conducted a randomized, double-blind trial at a small medical center in urban Taipei, Taiwan. We considered those who fulfilled the clinical and radiographic criteria for knee OA, defined by the American College of Rheumatology as a Kellgren-Lawrence grade 2 or 3, as potentially eligible. We excluded those who had a previous knee fracture or surgery and those who had received intra-articular knee injections of HA or corticosteroids within 6 months of the trial. Based on these criteria, 78 patients were eligible, and 76 agreed to be randomized to the co-injection or HA-only groups through block randomization. The groups had 38 patients each; all participants who completed the study follow-up were analyzed in the groups to which they were randomized and treated. There was no crossover. The patients in the co-injection group were treated with a one-shot co-injection of HA with corticosteroids (Hyruan Plus: molecular weight, 3000 kDa, 10 mg/mL HA, 2 mL with triamcinolone acetonide 10 mg/dL, 1 mL) in the first week followed by two injections of HA (10 mg/mL, 2 mL) at a 1-week interval. The patients in the HA-only group received three HA injections (Hyruan Plus: molecular weight, 3000 kDa, 10 mg/mL HA, 2 mL) administered at a 1-week interval. A senior physiatrist performed ultrasound-guided knee injections using the lateral suprapatellar approach. The physiatrist, participants, and outcome assessor were all blinded to the injection contents. No differences were observed between the two groups regarding primary demographic data, baseline WOMAC and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores, and physical functional performance. Three participants experienced localized swelling after the injections, and all symptoms improved after a few days of localized ice pack application. A total of 3.9% of patients (three of 76) had adverse events (mainly localized swelling of the knee, with or without accompanying pain), with no between-group differences in the frequency of adverse events. No severe side effects were reported during or after the injections. The patient-reported outcomes were the WOMAC and KOOS scores. The objective outcome was physical function performance (speed for 10-meter regular and fastest walking, and time for stair-climbing and chair-rising). The primary outcome timepoint was 6 months postinjection. A sample size of 34 participants was required in each group, based on a difference in WOMAC scores of 58 points, a significance level of 0.05, and a power of 0.8. We found no difference in improvement from baseline between the two groups regarding patient-reported outcomes at any follow-up timepoint, from 1 week after injection to 6 months. At 6 months post-treatment, compared with baseline, there were no between-group differences in improvement between the co-injection group and the HA-only group in terms of WOMAC pain scores (mean difference 1 [95% CI -2 to 3]; p = 0.62), stiffness (mean difference -11 [95% CI -13 to -9]; p < 0.001), and physical function (mean difference -4 [95% CI -5 to -3]; p < 0.001) and KOOS scores for pain, other symptoms, activities of daily living, sports and recreation, and quality of life. Except for chair-rising time at 6 months, which may have represented spurious significance because of the number of comparisons, compared with baseline, we found no differences in improvement between the two groups regarding the regular and fastest walking speed and stair ascent and descent time. We found that a single co-injection of corticosteroids along with HA did not confer any additional benefit regarding patient-reported outcomes or physical function compared with a three-injection regimen of HA. Therefore, we do not recommend a one-shot co-injection of corticosteroids alongside the three-injection regimen of HA for patients with knee OA, and because prior research found HA to be ineffective, HA should not be used with or without corticosteroids for patients with knee OA. Level I, therapeutic study.

Differences in Kinematic Changes From Self-Selected to Fast Speed Gait in Asymptomatic Adults With Radiological Signs of Femoro-Acetabular Impingement.

Femoro-acetabular impingement (FAI) may present as alterations in the skeletal morphology of the hip. Repercussions of FAI can be witnessed in self-selected speed walking as well as physical exercise such as running or fast speed walking. The aim of this study was to investigate changes in kinematics at different gait speeds in subjects presenting with radiological findings invoking FAI. One hundred thirty asymptomatic adults underwent biplanar X-rays with a calculation of 3D hip parameters: acetabular anteversion, abduction and tilt, vertical center edge angle (VCE), femoral anteversion, neck-shaft angle, acetabular coverage of the femoral head, femoral head diameter and neck length. Parameters were classified according to FAI clinical thresholds. Two groups were created: Control group (63 subjects having up to one subnormal hip parameter in favour of FAI) and Radiographic FAI group (67 subjects having ≥2 subnormal hip parameters that might cause FAI). All subjects underwent 3D gait analysis at self-selected and fast speed, from which kinematic parameters were generated. Arithmetic differences between fast and self-selected speed gait were considered as gait changes. Subjects in the Radiographic FAI group had decreased acetabular tilt (24 vs. 19˚), anteversion (19 vs. 16˚), abduction (55 vs. 53˚), femoral anteversion (18 vs. 14˚) and increased VCE (29 vs. 33˚, all p<0.05), compared to controls.Changes from self-selected to fast speed showed that subjects in the Radiographic FAI group had lower range of motion (ROM) pelvic rotation (7 vs. 4˚) and ROM hip flexion/extension (10 vs. 7˚), reduced hip extension (-4 vs. -2˚) and step length (16 vs. 13 cm; all p<0.05). The Radiographic FAI group had decreased acetabular abduction, anteversion and femoral anteversion in favour of FAI. When adapting from self-selected to fast speed gait, the Radiographic FAI group seemed to limit pelvic rotation and hip flexion/extension resulting in a decrease in step length. These kinematic limitations were previously reported in subjects with symptomatic FAI. Gait analysis could be considered as a functional diagnostic tool to assess FAI along with radiological assessment.

The Importance of Hip Abductor and Adductor Muscles in Balance and Mobility Tasks After a Stroke: A Systematic Review

The aim of this systematic review was to identify the association between muscle strength, activation, and structure of the hip abductor-adductor muscles and balance and mobility tasks in individuals post stroke. The present systematic review is comprised of 37 research articles, with 911 individuals that had a stroke. The extracted data included the study population, sample size, sex, stroke side of paresis, time poststroke, and evaluated measurements. We concluded that stronger hip abductors and adductors (both paretic and nonparetic legs) resulted in quicker voluntary step, and faster walking speed and cadence. Also, stronger paretic hip abductors were associated with a faster completion of the timed up and go test, higher ambulation ability, better control of the centre of mass, and quicker stair climbing. Overall, it demonstrated a lateral induced step to the paretic side, increased muscle activation of the gluteus medius of the paretic leg, and increased nonparetic hip abductor muscle activation. The strength and ability to activate the hip abductor and adductor muscles appears to be related to better performance during balance or mobility tasks in individuals with stroke. Therefore, the present systematic review results suggest that improving muscle strength and activation of the hip abductor and adductor muscles might help individuals with stroke to avoid falls.